This is one of the few aggressive sexual manuevers available to women. It occurs when the woman is riding the man like a bike. After she orgasms but before the man does, she gets off and attempts to break his boner in half, much like a bike thief attempting to break a lock. This causes the man a great deal of pain, as boners are not meant to be broken.

I got mine and this mother fucker slapped my ass too hard so I gave him the bike thief and broke his boner in half.